Trimming machine



June '17, 1952 H. c. PAULS'EN 2,600,427

TRIMMING MACHINE Filed Dec. 22, 1950 2 SHEETS'SHEET 1 Inventor Hans C. Paulsen By his Attorney June 17, 1952 H. c. PAULSEN 2,600,427

TRIMMING MACHINE Filed Dec. 22, 1950 2 SHEETSSHEET 2 Inventor Hans C Rzulsen By his Att omey Patented June 17, 1952 UNITED STATES PATENT GFFICE Claims.

This invention relates to sole roundin machines of the type disclosed in my United States Letters Patent No. 2,564,718; granted on August 21, 1951, on an application of mine and, more particularly, is concerned with improving the cutting action of this machine.

A sole is simultaneously trimmed and chamfered, in my prior machine, in conformity to a pattern against which the sole is held by a clamp having a flexible sole-engaging member which overlaps and is. supported outwardly of the pattern. Clamping pressure, upon being applied to the sole, causes the flexible member'of the clamp not only to assume; a dished formation; whereby its pressure upon the sole is concentrated along a line opposite to the edge of the pattern, but also to be thus displaced to different extents at different points about the periphery of the pattern, according to variations in the thickness in the sole. Therefore, contact of the flexible member with the sole opposite to the edge of the pattern is continuous regardless of the existence of local high or low areas in the sole, and complete clamping of the sole is insured at the edge of the pattern, that is, along the line where the sole is to be trimmed.

The tool-head of my prior machine comprises a knife having integral trimming and chamiering blades, the chamfering blade being arranged to chamfer the trimmed edge of the sole close behind the edge of the trimming knife. Moreover, end-surfaces upon the trimming and chamfering blades yieldingly bear upon the clamp at points slightly spaced from each other peripherally of the pattern. It will now be evident that because of the variable displacement of the flexiblemember of the clamp, caused by the varying thick.- ness of the sole, its surface upon which the blades bear will have a verysli'ght rising orfalling'sl'ope, peripherally cf the pattern, and. that at. such places one or the other of the trimming. and chamfering blades, but not both, will engage. the clamp. Any such separation between a blade and the clamp is hardly measurable, and too small to prevent the severance of the chip from the sole, but the bladewhichengagesthe clamp makes the cleaner out.

In view of the foregoing; one object of the in.- vention is to provide an improved: arrangement of trimming and chamfering-v knives in: a, machine of the type referredto which issodesigned: reference toa clamp of: variable slope uponzwhi'ch the knives-are to run that both knives will remain firmly in engagement withthe'clampat'all -times throughout therounding operation.

This end is attained, in accercl-ance withv one feature of the invention, by the use of separate trimming and chamfering' knives, the edge of the chamfering knife being disposed immediately behind the trailing portion of the trimming knife, and each knife being mounted to move independently of the other in response to variations in the level or slope of the portion of the clamp which it engages. Moreover, means is provided for urging each knife individually into engagement with the clamp, and. hence the: continuous contact of both kniveswith the clamp is insured.

The yielding action of the knives occurs, in the illustrated machine, as a swinging movement about a pivot which is so located, furthering another object of the invention, as tominimize any change in the shape or' size of soles of difierent thicknesses made with the use of the same pattern. To this end, and in accordance with another feature of. the. invention; the knives are mountedv to swing about an axis disposed substantially at the level of the side of the pattern engaged by the sole. As a result of this construction, the arcuate movement of the knives between difierent positions heightwise of the pattern will have a negligible component normal tothe edge of. the pattern.

The invention is also concerned with insuring the: greatest possible freedom inthe cutting action' of the tool-head and, more particularly, with avoiding any jamming of the chamfering chip between the chamfering and trimming knives. The chamfering chip is necessarily bent somewhat, outwardly from the sole edge and. toward the trailing portion of the trimming knife. b ecause-of the presence of the-chamfering bladebetween the chip and the c'hamfered portion of the sole; This bending action of the chip occurs at its. outward edge somewhat inv advance of the cutting edge of the charnfering knife, which is located. contiguous to the trailing portion of the trimmingknife forpurposesof keeping the points where: the two knives operate as: close as possible to each other, and to the: point of engagement of. thetool-headwith the pattern.

In order to insure againstiany interference be tween the chamfering. chip and the trimming knife,v and inaccordance With.- another feature of the invention, the trailing portion ,of the trim.- mingknife is chamfered obliquely and forwardlly thereof froma pointwelllbelowtheedge; off the chamfering. knife. Thisformationof the trimming knife provides ample: clearance space for all part'sofithe chamfering chip, and particularly that in advance of the cutting edge of the chamfering knife, so that any bending action which may be imparted to the chamfering chip, and its passage between the knives will not be impeded.

These and other features of the invention will now be described in detail with reference to the drawings, and will be defined in the claims.

In the drawings,

Fig. 1 is a side elevation of an illustrative toolhead embodying the present invention, and showing the relation between the clamps and the toolhead before the work is presented to the machine;

Fig. 2 is a plan view, partly in section, of the tool-head, as seen from the level of the line II-ll i F 1;

Fig. 3 is a sectional elevation illustrating the tool-head, the pattern, the work, and the clamps in their operative relation;

Fig. 4 is a view in perspective of the upper trimming and chamfering knives, the knives being shown as considerably enlarged in size, and in their normal operating relation; and

Fig. 5 is a plan view showing the upper knives and their cutting action upon a sole.

As in the case of the tool-head in my abovementioned prior machine, the illustrated toolhead 280 cooperates with a pattern P, and a pair of clamps I0, I2, to trim and chamfer simultaneously a pair of soles S, S which are held against the pattern by the clamps.

The clamp structure disclosed herein is identical to that structure in my prior machine, and such structure will now be briefly described and designated by the same reference characters which were used in my prior patent.

The clamps I0, I2 comprise rigid bases which are substantially larger than the largest pattern to be used in the machine, and have a peripheral contour generally similar to that of the pattern. The inner and adjacent surfaces of the bases are recessed leaving peripheral flanges I I4, I I5 which extend continuously around their rims. To these flanges there are secured flexible spring steel plates or diaphragms II8, I20, as by brazing or any other suitable method.

The lower clamp I2 is fixed, but the upper clamp I8 may be lowered to cause clamping pressure to be exerted by the clamps upon the soles, as described in my prior patent. In response to this clamping pressure the plates or diaphragms II8, I yield into the recesses of the respective clamps and assume a dished formation, the central portions of the plates bulging away from the soles. Accordingly, the clamping pressure is concentrated upon narrow marginal areas of the soles bounded by the periphery of the pattern. Moreover, if a sole is of variable thickness, as is quite common, the diaphragms will be displaced to difierent extents at different points about the periphery of the pattern, the plates being displaced farther where they engage the thicker portions of the soles than at the thinner portions thereof. Thus, it is insured that clamping pressure will be applied to the soles continuously along the line Where they are to be trimmed, notwithstanding variations in the thickness of the soles. It will now be evident that the surface of each diaphragm which overlaps the edge of the pattern may be disposed at slightly different levels at different points about the periphery of the pattern, and that certain portions of each diaphragm may slope (peripherally of the pattern) very slightly toward or away from the adjacent surface of the pattern. It is in connection with this characteristic of the clamps that an important novel feature in the illustrated tool-head has been developed. However, before describing this and the other features of the invention in detail, structure common to the illustrated machine and my prior machine, and relating to the mounting for the tool-head, will first be described.

The tool-head comprises bars l34, I48 which are secured to the opposite sides of the central portion of a U-shaped yoke I38. This yoke is arranged to swing freely on pins I38, I48 which are fixed in the arms of a bracket I42, the latter being secured to and. effectually integral with an arm 58. It is to be understood that the arm. during the normal operation of the machine, is urged toward the center of the clamps to cause a shield I52, spanning the ends of the bars and fixed to the bar I34 by a screw I50, always to be seated upon the periphery of the pattern P.

The tool-head is thus maintained normal to the edge of the pattern, where it is engaged by the shield, as the tool-head is transferred around the pattern, the yoke I35 swinging freely about the axis of the pins I38, I40 to one side or the other depending upon the change in the contour of the pattern. This swinging movement of the yoke is damped by a spring I 68 which is stretched between the yoke and the bracket I42. The yoke I36 and the parts carried thereby are also arranged to move freely axially of the pins I38, I40, and their weight is substantially counterbalanced by a spring I44 surrounding the pin I40.

A V-shaped plow I86 is arranged to smooth layers of reinforcing material R, R. such as cotton duck, against the portions of the insoles which overlap the pattern, and also guides the reinforcing material onto each of two supports I66 which are formed on the upper and lower sides of the bar I48, and hold the reinforcing material closely against the insoles immediately in advance of the trimming knives. The supports I66 also position the tool-head centrally with respect to the mid-plane of the pattern, the tool-head being free to slide vertically on the pins I38, I40. The plow is mounted to slide on the bar I48 lengthwise thereof, and is held on the bar by screws I82 which extend through elongated slots in the plow and are threaded into the bar. A spring I84 yieldingly holds the plow against the edge of the pattern.

The improved features of the tool-head 20B disclosed herein reside in the construction and mounting of its trimming and chamfering knives, as a result of which the continuous engagement of each knife with the clamp with which it cooperates is insured, as well as uniformity in the size of soles of difi'erent thicknesses made from the same pattern.

Cooperating with the upper clamp I8 are an upper trimming knife 282, and a separate upper chamfering knife 204, each of which is mounted to swing independently of the other about the axis of a pin 208 which is inserted into alined holes in the bars I34, I48. These trimming and chamfering knives are fixed to the outer ends of holders 288, 240, respectively, which are mounted at their inner ends to swing freely upon the pin 206. A similar set of knives comprising a trimming knife (not shown, but directly below the trimming knife 202), and a chamfering knife 2I2 directly below the chamfering knife 204, are mounted to swing independently of each other into engagement with the lower clamp I2 about the axis of another pin 2 I4 mounted in the bars I34, I48 directly below the above-mentioned pin 206. A holder (not shown) for the lower trimming knife and a holder 2I6 for the lower chamfering knife, these holders being exactly similar to the holders 2G8, 2H3, respectively, are mountedto swing upon the pin 2M. The ends of a spring 2I8 received in recesses in the holders 2H3, 2H5 bear against the holders, and cause the chamfering knives 204, 2I2, to be held in engagement with the clamps I0, I2, respectively. A pin 220 fixed in the bars I32, I48, and encircled by the spring, positions the latter within the recesses of the holders. Another spring 222, similar to the spring 2I8, encircles the pin 229, is received within recesses in the holders for the trimming knives, and urges them apart into engagement with the clamps I0, I2. The strength of the spring 222 is such as tocause each trimming knife to be held against the clamp which it engages with a pressure of about 30 lbs. A lesser pressure, of about 20 lbs. is sufiicient to hold the chamfering knives against the clamps, and the spring H8 is correspondingly weaker than the spring 222.

The trimming knife 202 has a vertical cutting edge 224 which is contiguous to both the adjacent support l66, and the inner side of the shield I 52. An end-surface 226 upon the upper extremity of the knife is arranged to slide upon the plate H8 of the clamp Ill. Rearwardly of this end-surface the trimming knife is relieved, at 228, to insure the engagement of the end surface 226 with the clamp.

It is evident that each trimming knife will occupy different positions heightwise of the pattern depending upon the thickness of the sole being operated upon. For example, the knife 292 will swing more or or less with respect to the pin 2% in response to changes in the level of the clamp Iii, whether such changes are caused by variations in the thickness of the same sole, or by variations in thickness between different soles. Because this movement of the knives is arcuate, the pins 286, 2I4 are located well above and below the center of the tool-head and the midplane of the pattern. The optimum spacing of the pins is obtained when they are disposed substantially at the levels of the sides of the pattern, as illustrated herein, because the arcuate movement of the knives when thus mounted has a negligible component directed toward and away from the edge of the pattern, and no discernible tendency to vary the shape or size of the soles.

The separate pivotal mounting of the trimming and chamfering knives becomes of particular value toward the end of the useful life of the trimming knives, that is, when their resharpening is required. The trimming knives usually become dull sooner than the chamfering knives, and the dulling is the greatest at the extremities of their cutting edges because the parts of the soles engaged by the ends of the knives are of the firmer material and are further condensed by the clamping pressure. If a trimming knife is used too long without sharpening it may be pushed slightly away from the clamp by the resistance of the firmer material of the sole, and thus fails to out completely through the sole. However, the chamfering knife, being individually pivoted, is unaffected by the above-described action of the trimming knife and, in fact, in removing the chamfering chip from the sole eliminates any evidence of incompleteness of the trimming cut.

The chamfering knife 204 has a cutting edge 230 which extends obliquely across the line of cut of the trimming knife 202, and terminates at an end-surface 232' upon the extremity of the chamfering knife which is adapted to slide on the plate H8. The chamfering knife is also relieved at 234, rearwardly of its end-surface 232 so as to insure the engagement of the endsurface with the plate. The cutting edge 230 of the chamfering knife is disposed immediately behind the trailing portion of the trimming knife, and extends beyond the line of the cut of the trimming knife outwardly from the sole edge owing to the provision of a groove 236 at the lower end of the cutting edge 230. This formation of the knife permits the cutting edge 23!! to be readily sharpened far enough beyond the point where it normally engages the trimmed sole edge to insure that a well sharpened portion of the cutting edge will always be presented to the work, regardless of minor variations in the position of the chamfering knife toward and away from the shield I 52 resulting from the tolerances permitted in the manufacture of the machine parts.

The chamfering knife 204 forms a small chip C of triangular cross-section which is bent outwardly away from the sole edge by an outwardly flaring surface 238 on the chamfering knife, and it is evident that a clear passage between the knives must be provided for this chip. Moreover, the chip clearance between the knives must be greater than would be expected, considering only the size of the chip itself, for the reason that its bending extends, at the outer edge of the chip, forwardly of the edge of the chamfering knife. Considering this action of the chamfering chip, adequate clearance between it and the chamfering knife is provided by forming an oblique chamfer 240 on the trailing portion of the trimming knife which extends from below the cutting edge 230 of the chamfering knife forwardly toward the cutting edge 224 of the trimming knife, and outwardly from its line of cut. Accordingly, adequate clearance is provided. for the chamfering chip both heightwise and laterally thereof, so that its passage away from the knives cannot be impeded because of either the bending action of the chip or jamming of the chip within the opening defined by the knives and the clamp upon which they bear.

In the operation of a machine embodying the present invention, let it be assumed that soles S, S are held against the opposite sides of the pattern P by the clamps I0, I2 and that the toolhead 2% is transferred about the pattern under its guidance, as is fully explained in my prior patent mentioned above, simultaneously to trim and chamfer the soles. If the thickness of the sole S varies, the plate H8 will slope, ever so little, toward or away from the pattern, and the trimming and chamfering knives 202, 262 will swing independently of each other in response to variations in the level of the plate, each knife maintaining the contact of its own end-surface with the plate at all times because of its individual pivotal mounting upon the pin 236. It is thus insured that each knife will alway out entirely through the surface of the sole S which engages the plate II8.

It is further to be noted that because the chamfer 2 39 on the trimming knife extends well below the edge 23!) of the chamfering knife, any relative heightwise movement of the knives, which may occur as they pass over a sloping portion of the plate H8, cannot cause a restriction in the opening between them.

Although the cutting action of my improved tool-head has been described above with refere ce to the upper trimming and chamfering knives 202, 20 it is to be understood that the lower trimming and chamfering knives are exactly similar to the upper knives, and operate in the same manner to trim the lower sole S and remove the chamfering chip therefrom.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine for rounding soles in conformity to a pattern, a clamp cooperating with the pattern to hold a sole thereagainst, said clamp comprising a flexible sole-engaging memher which is arranged to overlap the pattern and is deformable according to variations in the thickness of the sole into continuous contact therewith opposite to the edge of the pattern, a tool-head for simultaneously trimming and chamfering the sole under the guidance of the pattern, said tool-head comprising a trimming knife and a chamfering knife each of which has an end-surface arranged to seat upon said sole-engaging member, each of said knives being mounted to move independently of the other in response to variations in the level of said soleengaging member, and means for urging said knives into engagement with said sole-engaging member.

2. In a machine for rounding soles in conformity to a pattern, a clamp cooperating with the pattern to hold a sole thereagainst, said clamp comprising a flexible sole-engaging memher which is arranged to overlap the pattern and is deformable according to variations in the thickness of the sole into continuous contact therewith opposite to the edge of the pattern, a tool-head for simultaneously trimming and chamfering the sole under the guidance of the pattern, said tool-head comprising a trimming knife and a chamfering knife each of which has an end-surface arranged to seat upon said soleengaging member, separate holders for said knives mounted to swing independently of each other in response to variations in the level of said sole engaging member, and a spring cooperating with each of said holders to cause said knives to be held in engagement with said soleengaging member.

3. In a machine for rounding soles in conformity to a pattern, a clamp cooperating with the pattern to hold a sole thereagainst, said clamp comprising a flexible sole-engaging member which is arranged to overlap the pattern and is deformable according to variations in the thickness of the sole into continuous contact therewith opposite to the edge of the pattern, a tool-head for simultaneously trimming and chamfering the sole under the guidance of the pattern, said tool-head comp-rising a trimming knife and a chamfering knife mounted to swing independently of each other about a common axis at substantially the level of the sole-engaging surface of the pattern, and means for urging said knives into engagement with said soleengaging member.

4. In a machine for rounding soles in conformity to a pattern, opposed clamps cooperating with the pattern to hold a sole against each side thereof, each of said clamps comprising a flexible sole-engaging member which is arranged to overlap the pattern and is deformable according to variations in the thickness of the sole into complete contact therewith opposite to the edge of the pattern, a tool-head movable about said pattern under the guidance of its edge for simultaneously trimming and chamfering the soles, said tool-head comprising two pairs of knives, each pair consisting of a trimming knife and a chamfering knife mounted and arranged to seat upon one of said sole-engaging members, means for yieldingly urging said trimming knives independently of said chamfering knives into engagement with said clamps, and means for urging said chamfering knives independently of said trimming knives into engagement with said clamps.

5. In a machine for rounding soles in conformity to a pattern, opposed clamps cooperating with the pattern to hold a sole against each side thereof, each of said clamps comprising a flexible sole-engaging member which is arranged to overlap the pattern and is deformable according to Variations in the thickness of the sole into continuous contact therewith opposite to the edge of the pattern, a tool-head movable about said pattern under the guidance of its edge for simultaneously trimming and chamfering the soles, said tool-head co p upper and lower trimming knives mounted to swing about spaced axes disposed at equal distances above and below the mid-plane of the pattern respectively, upper and lower chamfering knives mounted to swing about said axes independently of said trimming knives, and means for yieldingly holding said trimming and chamfering knives in engagement with said clamps,

6 In a machine for rounding soles in conformity to a pattern, opposed clamps cooperating with the pattern to hold a sole against each side thereof, each of said clamps comprising a flexible soleengaging member which is arranged to overlap the pattern and is deformable according to variations in the thickness of the sole into continuous contact therewith opposite to the edge of the pattern, a tool-head movable about said pattern under the guidanceof its edge for simultaneously trimming and chamfering the soles, said tool-head comprising upper and lower trimming knives mounted to swing about spaced axes at substantially the levels of the sides of the pattern, upper and lower chamfering knives mounted to swing about said axes independently of said trimming knives, and means for yieldingly holding said trimming and chamfering knives in engagement with said clamps.

7. In a machine for rounding soles in conformity to a pattern, opposed clamps cooperating with the pattern to hold a sole against each side thereof, each of said clamps comprising a flexible soleengaging member which is arranged to overlap the pattern and is deformable according to variations in the thickness of the sole into continuous contact therewith opposite to the edge of the pattern, a tool-head movable about said pattern under the guidance of its edge for simultaneously trimmin and chamfering the soles, said tool-head comprising upper and lower trimming knives mounted to swing about spaced axes into engagement with said clamps, means for yieldingly holding said trimming knives against said clamps, upper and lower chamfering knives mounted to swing about said axes independently of said trimmin knives into engagement with said clamps, the cutting edges of said chamfering knives being contiguous to the trailing portions of said trimming knives, and means for yieldingly holding said chamfering knives in engagement with said clamp-s.

8. In a machine for rounding soles in conformity to a pattern, opposed clamps cooperating with the pattern to hold a sole against each side thereof, each of said clamps comprising a flexible sole-engaging member which is arranged to overlap the pattern and is deformable according to variations in the thickness of the sole into continuous contact therewith opposite to the edge of the pattern, a tool-head movable about said pattern under the guidance of its edge for simultaneously trimming and chamfering the soles, said tool-head comprising upper and lower pairs of knives, each pair consisting of a trimming knife and a chamfering knife, a holder for each knife, a common pivot at one side of the mid-plane of the pattern for the holders for the upper pair of knives about which pivot said upper knives are adapted toswing independently of each other into engagement with one of said clamps, the holders for said lower pair of knives being mounted to swing independently of each other about a common pivot at the other side or the mid-plane of the pattern, a spring acting upon the holders for said trimming knives to urge said trimming knives into engagement with said clamp, and a second spring acting upon the holders for said chamfering knives to urge the chamfering knives independently of the trimming knives into engagement with the clamps.

9. In a machine for rounding soles in conformity to a pattern, a clamp cooperating with a pattern to hold a sole thereagainst, said clamp comprising a flexible sole-engaging member arranged to overlap the pattern and which is deformable according to variations in the thickness of the sole into continuous contact with the sole opposite to the edge of the pattern, a tool-head for simultaneously trimming and chamfering the sole under the guidance of the pattern, said tool-head comprising a trimming knife and a chamfering knife mounted and arranged to bear against said sole-engaging member and to move independently of each other in response to variations in the level of said sole-engaging memher, said chamfering knife having a cutting edge extending from outside the line of cut of said trimming knife obliquely across the trimmed edge of the sole contiguous to said sole-engaging member.

10. In a machine for rounding soles in conformity to a pattern, a clamp cooperating with a pattern to hold a sole thereagainst, said clamp comprising a flexible sole-engaging member ar-' ranged to overlap the pattern and which is deformable according to variations in the thickness of the sole into continuous contact with the sole opposite to the edge of the pattern, a toolhead for simultaneously trimming and chamfering the sole under the guidance of the pattern, said tool-head comprising a trimming knife and a chamfering knife the extremities of which are arranged to bear against said sole-engaging member, said chamierin knife being mounted with its cutting edge disposed immediately behind the trailing portion of said trimming knife, the trailing portion of said trimming knife being obliquely chamfered from below the edge of said chamfering knife forwardly thereof and outwardly from the trimmed sole edge, whereby clearance for the chamfering chip is provided in advance of the edge of the chamfering knife.

HANS C. PAULSEN.

No references cited, 

